1. Field of the Invention
The present invention relates to a replaceable liquid storage container suitable for the use in an ink jet recording apparatus, or the like, and a liquid discharge recording apparatus using the container. Specifically, it relates to a liquid storage container for storing a dispersion type ink (liquid) such as a pigment, and a liquid discharge recording apparatus using the container.
2. Related Background Art
The ink jet recording method is for executing a desired recording operation by jumping ink droplets from a minute ejection opening provided in an ink jet head, and having the ink droplets impact on a recording medium.
As an ink used for the ink jet recording, a liquid using a dye has mainly been used. However, according to a recorded matter recorded with a liquid using a dye, the performance required for the applications regarding the light resistance and the weather resistance important, such as the exterior display printed matter, or the like cannot be provided, and thus a liquid using a pigment is used instead thereof.
Since the pigment is not a dissolution type but a dispersion type, according to an ink (liquid) using a pigment, pigment particles are precipitated in an ink tank as a liquid storage part.
In the case of an out carriage tank with an ink tank fixed statically (such as a main tank used for a recording apparatus disclosed in the specification of the U. S. Patent Application Disclosure No. 2002/109758, or the like), it has been revealed that the pigment precipitation phenomenon cannot be ignored depending on the use frequency, the use interval, the number of recording (number of recorded sheets), or the like of the recording apparatus. Particularly in the case of the out carriage tank, the ink capacity tends to be made larger for the purpose of reducing the replacement frequency of the ink tank as the liquid storage container for the user with the need of high user frequency. Also in this regard, there has been the concern about the pigment precipitation not to be ignorable for the user.
For example, in the case the ink tank is left for a long time in a state mounted on the ink jet recording apparatus, the pigment particles are gradually precipitated inside the ink tank. As a result, the density inclination of the pigment particles is generated from the bottom part to the upper part inside the ink tank (liquid storage container) so that a layer with a high pigment particle density having an excessively thick color is generated in the bottom part, and a layer with a low pigment density having an excessively thin color is generated in the upper part.
Then, in the case an ink is supplied from the ink tank having a configuration of guiding out the ink in the ink storage chamber from the ink tank bottom part, since the ink is supplied first from the layer with the high pigment particle density, a problem (technological task) is involved in that a printed matter with an excessively thick color is produced, and then the density difference to the degree visually recognizable is generated in the printed matters between the use initial stage and the use latter stage of the ink tank. This phenomenon becomes particularly remarkable in the color printing for providing an image by the color thickness.
In order to solve the technological task, for example, as it is disclosed in the Japanese Patent Application Laid Open (JP-A) Nos. 2001-270131 and 2001-293880, a tube-like pipe with a plurality of holes is provided in an ink tank from the ink supply opening of the ink tank so that the ink is vacuumed not only from the part in the vicinity of the ink supply opening inside the ink tank but also from a large number of portions in the vertical direction in the ink tank, wherein a portion for temporarily storing the ink vacuumed from the large number of the portions is provided such that the density irregularity of the ink in the vertical direction being left for a long time in the ink tank can be alleviated by supplying the ink from the storing portion.
However, since the relationship with respect to the pigment precipitation characteristic is not taken into consideration in the holes provided in the tube-like pipe of the ink tank disclosed in the above-mentioned Japanese Patent Application Laid-Open (JP-A) Nos. 2001-270131 and 2001-293880, the density and the mount of the ink flown in from the outside of the tube-like pipe through the holes provided in the tube-like pipe are not administered so that the ink density in the tube-like pipe becomes consequently different from the original ink density, and thus the problem of generation of the density difference in the recorded matters in the use initial stage and the use latter stage of the ink tank had not been solved sufficiently.
Moreover, as means for solving the coloring material precipitation, there is a method of providing propeller-like agitating means and driving means for rotating the same inside a main tank for rotating the agitating means regularly at a predetermined rate. However, the agitating mechanism is extremely expensive. Moreover, in the case the driving means (motor) is provided in the vicinity of an ink channel, a leaked ink adhered on a power source connector part of the driving motor can be the cause of breakdown such as short circuit so that there is the risk of leading to generation of smoke, fire, or the like.